Table 1. Positions, widths (FWHM in parentheses), and suggested vibrational and isomer assignments of the transitions observed in the IRPD spectra of Np+-Wn compared to frequencies of most stable isomers calculated at the B3LYP-D3/aug-cc-pVTZ level. For comparison, available data for Wn with n ≤ 2 are also listed.
| Cluster | Exp (cm–1) | Vibration | Calc a (cm–1) | Isomer |
| W | 3657 b | ν 1 | 3656 (5, a1) | |
| 3756 b | ν 3 | 3755 (63, b2) | ||
| W2 | 3601 b | ν b | 3540 (341, a′) | |
| 3654 b | ν 1 | 3650 (9, a′) | ||
| 3735 b | ν f | 3727 (87, a′) | ||
| 3746 b | ν 3 | 3745 (84, a′′) | ||
| Np+-W | E 3072 (13) | ν CH | 3062 (59, a1) | Np+-W(18) |
| B 3635 (10) | ν 1 | 3641 (34, a1) | Np+-W(18) | |
| A 3722 (9) | ν 3 | 3729 (95, b1) | Np+-W(18) | |
| Np+-W2 | E 3068 (10) | ν CH | 3051 (143, a′) | Np+-W2(18) |
| ν CH | 3063 (108, b3u) | Np+-W2(1845) | ||
| D 3496 (33) | ν b | 3434 (696, a′) | Np+-W2(18) | |
| B 3646 (13) | ν 1 | 3649 (22, a′) | Np+-W2(18) | |
| ν 1 | 3642 (65, ag) | Np+-W2(1845) | ||
| C 3696 (14) | ν f | 3708 (84, a′) | Np+-W2(18) | |
| A2 3728 (10) | ν 3 | 3731 (186, b1u) | Np+-W2(1845) | |
| A1 3740 (9) | ν 3 | 3741 (99, a′′) | Np+-W2(18) | |
| Np+-W3 | E 3065 (24) | ν CH | 3123 (18) | Np+-W3(c1) |
| ν CH | 3079 (113) | Np+-W3(c2) | ||
| D3 3248 (broad) | 2βOH | |||
| D2 3402 (broad) | ν b | 3415 (162) | Np+-W3(c1) | |
| ν b | 3417 (85) | Np+-W3(c2) | ||
| D1 3507 (broad) | ν b | 3485 (313) | Np+-W3(c1) | |
| 3528 (197) | ||||
| ν b | 3472 (380) | Np+-W3(c2) | ||
| 3502 (335) | ||||
| C 3703 (28) | ν f | 3713 (79) | Np+-W3(c1) | |
| 3711 (137) | ||||
| 3708 (120) | ||||
| ν f | 3717 (68) | Np+-W3(c2) | ||
| 3715 (143) | ||||
| 3714 (126) | ||||
| Np+-W4 | E 3082 (4) | ν CH | 3087 (4) | Np+-W4(c) |
| D2 3210 (broad) | ν b | 3240 (56) | Np+-W4(c) | |
| 2βOH | ||||
| D1 3433 (broad) | ν b | 3319 (752) | Np+-W4(c) | |
| 3332 (778) | ||||
| 3375 (170) | ||||
| C 3703 (16) | ν f | 3710 (94) | Np+-W4(c) | |
| 3708 (122) | ||||
| 3708 (153) | ||||
| 3706 (18) | ||||
| Np+-W5 | D2 3230 (49) | ν b | 3180 (182) | Np+-W5(c1) |
| 2βOH | ||||
| D1 3365 (broad) | ν b | 3256 (1327) | Np+-W5(c1) | |
| 3281 (816) | ||||
| 3317 (429) | ||||
| 3356 (134) | ||||
| C 3700 (13) | ν f | 3712 (117) | Np+-W5(c1) | |
| 3710 (146) | ||||
| 3708 (84) | ||||
| 3707 (74) | ||||
| 3706 (29) |
aIR intensity (in km mol–1) and vibrational symmetry are listed in parentheses. For the νCH modes, only the by far most intense calculated vibration is listed.